Cardiomyopathy refers to diseases of the heart muscle. These diseases have many causes, signs and symptoms, and treatments.
In cardiomyopathy, the heart muscle becomes enlarged, thick, or rigid. In rare cases, the muscle tissue in the heart is replaced with scar tissue.
As cardiomyopathy worsens, the heart becomes weaker. It's less able to pump blood through the body and maintain a normal electrical rhythm. This can lead to heart failure or irregular heartbeats called arrhythmias. In turn, heart failure can cause fluid to build up in the lungs, ankles, feet, legs, or abdomen.
The weakening of the heart also can cause other complications, such as heart valve problems.
The types of cardiomyopathy are:
Cardiomyopathy can be acquired or inherited. "Acquired" means you aren't born with the disease, but you develop it due to another disease, condition, or factor. "Inherited" means your parents passed the gene for the disease on to you. Many times, the cause of cardiomyopathy isn't known.
Cardiomyopathy can affect people of all ages. However, people in certain age groups are more likely to have certain types of cardiomyopathy. This article focuses on cardiomyopathy in adults.
Some people who have cardiomyopathy have no signs or symptoms and need no treatment. For other people, the disease develops quickly, symptoms are severe, and serious complications occur.
Treatments for cardiomyopathy include lifestyle changes, medicines, surgery, implanted devices to correct arrhythmias, and a nonsurgical procedure. These treatments can control symptoms, reduce complications, and stop the disease from getting worse.
Hypertrophic cardiomyopathy is very common and can affect people of any age. Hypertrophic cardiomyopathy affects men and women equally, and about 1 out of every 500 people has the disease.
Hypertrophic cardiomyopathy happens when the heart muscle enlarges and thickens without an obvious cause. Usually the ventricles, the lower chambers of the heart, and septum (the wall that separates the left and right side of the heart) thicken. The thickened areas create narrowing or blockages in the ventricles, making it harder for the heart to pump blood. Hypertrophic cardiomyopathy also can cause stiffness of the ventricles, changes in the mitral valve, and cellular changes in the heart tissue.
Dilated cardiomyopathy develops when the ventricles enlarge and weaken. The condition usually starts in the left ventricle and over time can affect the right ventricle. The weakened chambers of the heart don’t pump effectively, causing the heart muscle to work harder. Over time, the heart loses the ability to pump blood effectively. Dilated cardiomyopathy can lead to heart failure, heart valve disease, irregular heart rate, and blood clots in the heart.
Restrictive cardiomyopathy develops when the ventricles become stiff and rigid but the walls of the heart do not thicken. As a result, the ventricles do not relax and don’t fill with the normal blood volume. As the disease progresses, the ventricles do not pump as well and the heart muscle weakens. Over time, restrictive cardiomyopathy can lead to heart failure and problems with the heart valves.
Arrhythmogenic right ventricular dysplasia is a rare type of cardiomyopathy that occurs when the muscle tissue in the right ventricle is replaced with fatty or fibrous tissue. This can lead to disruptions in the heart’s electrical signals and causes arrhythmias. Arrhythmogenic right ventricular dysplasia usually affects teens or young adults and can cause sudden cardiac arrest in young athletes.
Other types of cardiomyopathy are grouped into this category and can include:
Cardiomyopathy can be acquired or inherited. “Acquired” means you aren’t born with the disease, but you develop it due to another disease, condition, or factor.
“Inherited” means your parents passed the gene for the disease on to you. Researchers continue to look for the genetic links to cardiomyopathy and to explore how these links cause or contribute to the various types of the disease.
Many times, the cause of cardiomyopathy isn’t known. This often is the case when the disease occurs in children.
Hypertrophic cardiomyopathy usually is inherited. It’s caused by a mutation or change in some of the genes in heart muscle proteins. Hypertrophic cardiomyopathy also can develop over time because of high blood pressure, aging, or other diseases, such as diabetes or thyroid disease. Sometimes the cause of the disease isn’t known.
The cause of dilated cardiomyopathy often isn’t known. About one-third of the people who have dilated cardiomyopathy inherit it from their parents.
Certain diseases, conditions, and substances also can cause the disease, such as:
Certain diseases, conditions, and factors can cause restrictive cardiomyopathy, including:
Researchers think that arrhythmogenic right ventricular dysplasia is an inherited disease.
People of all ages and races can have cardiomyopathy. However, certain types of the disease are more common in certain groups.
Dilated cardiomyopathy is more common in African Americans than Whites. This type of the disease also is more common in men than women.
Teens and young adults are more likely than older people to have arrhythmogenic right ventricular dysplasia, although it's rare in both groups.
Certain diseases, conditions, or factors can raise your risk for cardiomyopathy. Major risk factors include:
Some people who have cardiomyopathy never have signs or symptoms. Thus, it's important to identify people who may be at high risk for the disease. This can help prevent future problems, such as serious arrhythmias (irregular heartbeats) or SCA.
You can't prevent inherited types of cardiomyopathy. However, you can take steps to lower your risk for diseases or conditions that may lead to or complicate cardiomyopathy. Examples include ischemic heart disease, high blood pressure, and heart attack.
Your doctor may advise you to make heart-healthy lifestyle changes, such as:
Your cardiomyopathy may be due to an underlying disease or condition. If you treat that condition early enough, you may be able to prevent cardiomyopathy complications. For example, to control high blood pressure, high blood cholesterol, and diabetes:
Some people who have cardiomyopathy never have signs or symptoms. Others don't have signs or symptoms in the early stages of the disease.
As cardiomyopathy worsens and the heart weakens, signs and symptoms of heart failure usually occur. These signs and symptoms include:
Other signs and symptoms may include dizziness; light-headedness; fainting during physical activity; arrhythmias (irregular heartbeats); chest pain, especially after physical exertion or heavy meals; and heart murmurs. (Heart murmurs are extra or unusual sounds heard during a heartbeat.)
Your doctor will diagnose cardiomyopathy based on your medical and family histories, a physical exam, and the results from tests and procedures.
Often, a cardiologist or pediatric cardiologist diagnoses and treats cardiomyopathy. A cardiologist specializes in diagnosing and treating heart diseases. A pediatric cardiologist is a cardiologist who treats children.
Your doctor will want to learn about your medical history. He or she will want to know what signs and symptoms you have and how long you've had them.
Your doctor will use a stethoscope to listen to your heart and lungs for sounds that may suggest cardiomyopathy. These sounds may even suggest a certain type of the disease.
For example, the loudness, timing, and location of a heart murmur may suggest obstructive hypertrophic cardiomyopathy. A "crackling" sound in the lungs may be a sign of heart failure. (Heart failure often develops in the later stages of cardiomyopathy.)
Physical signs also help your doctor diagnose cardiomyopathy. Swelling of the ankles, feet, legs, abdomen, or veins in your neck suggests fluid buildup, a sign of heart failure.
Your doctor may notice signs and symptoms of cardiomyopathy during a routine exam. For example, he or she may hear a heart murmur, or you may have abnormal test results.
Your doctor may recommend one or more of the following tests to diagnose cardiomyopathy.
During a blood test, a small amount of blood is taken from your body. It's often drawn from a vein in your arm using a needle. The procedure usually is quick and easy, although it may cause some short-term discomfort.
Blood tests give your doctor information about your heart and help rule out other conditions.
A chest x ray takes pictures of the organs and structures inside your chest, such as your heart, lungs, and blood vessels. This test can show whether your heart is enlarged. A chest x ray also can show whether fluid is building up in your lungs.
An EKG is a simple test that records the heart's electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through each part of the heart.
This test is used to detect and study many heart problems, such as heart attacks, arrhythmias (irregular heartbeats), and heart failure. EKG results also can suggest other disorders that affect heart function.
A standard EKG only records the heartbeat for a few seconds. It won't detect problems that don't happen during the test.
To diagnose heart problems that come and go, your doctor may have you wear a portable EKG monitor. The two most common types of portable EKGs are Holter and event monitors.
Holter and event monitors are small, portable devices. They record your heart's electrical activity while you do your normal daily activities. A Holter monitor records the heart's electrical activity for a full 24- or 48-hour period.
An event monitor records your heart's electrical activity only at certain times while you're wearing it. For many event monitors, you push a button to start the monitor when you feel symptoms. Other event monitors start automatically when they sense abnormal heart rhythms.
Echocardiography (echo) is a test that uses sound waves to create a moving picture of your heart. The picture shows how well your heart is working and its size and shape.
There are several types of echo, including stress echo. This test is done as part of a stress test (see below). Stress echo can show whether you have decreased blood flow to your heart, a sign of coronary heart disease.
Another type of echo is transesophageal (tranz-ih-sof-uh-JEE-ul) echo, or TEE. TEE provides a view of the back of the heart.
For this test, a sound wave wand is put on the end of a special tube. The tube is gently passed down your throat and into your esophagus (the passage leading from your mouth to your stomach). Because this passage is right behind the heart, TEE can create detailed pictures of the heart's structures.
Before TEE, you're given medicine to help you relax, and your throat is sprayed with numbing medicine.
Some heart problems are easier to diagnose when your heart is working hard and beating fast. During stress testing, you exercise (or are given medicine if you're unable to exercise) to make your heart work hard and beat fast while heart tests are done.
These tests may include nuclear heart scanning, echo, and positron emission tomography (PET) scanning of the heart.
You may have one or more medical procedures to confirm a diagnosis or to prepare for surgery (if surgery is planned). These procedures may include cardiac catheterization (KATH-e-ter-i-ZA-shun), coronary angiography (an-jee-OG-ra-fee), or myocardial (mi-o-KAR-de-al) biopsy.
This procedure checks the pressure and blood flow in your heart's chambers. The procedure also allows your doctor to collect blood samples and look at your heart's arteries using x-ray imaging.
During cardiac catheterization, a long, thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck and threaded to your heart. This allows your doctor to study the inside of your arteries for blockages.
This procedure often is done with cardiac catheterization. During the procedure, dye that can be seen on an x ray is injected into your coronary arteries. The dye lets your doctor study blood flow through your heart and blood vessels.
Dye also may be injected into your heart chambers. This allows your doctor to study the pumping function of your heart.
For this procedure, your doctor removes a piece of your heart muscle. This can be done during cardiac catheterization. The heart muscle is studied under a microscope to see whether changes in cells have occurred. These changes may suggest cardiomyopathy.
Myocardial biopsy is useful for diagnosing some types of cardiomyopathy.
Some types of cardiomyopathy run in families. Thus, your doctor may suggest genetic testing to look for the disease in your parents, brothers and sisters, or other family members.
Genetic testing can show how the disease runs in families. It also can find out the chances of parents passing the genes for the disease on to their children.
Genetic testing also may be useful if your doctor thinks you have cardiomyopathy, but you don't yet have signs or symptoms. If the test shows you have the disease, your doctor can start treatment early, when it may work best.
People who have cardiomyopathy but no signs or symptoms may not need treatment. Sometimes, dilated cardiomyopathy that comes on suddenly may go away on its own. For other people who have cardiomyopathy, treatment is needed. Treatment depends on the type of cardiomyopathy you have, the severity of your symptoms and complications, and your age and overall health. Treatments may include:
The main goals of treating cardiomyopathy include:
Your doctor may suggest lifestyle changes to manage a condition that’s causing your cardiomyopathy including:
Many medicines are used to treat cardiomyopathy. Your doctor may prescribe medicines to:
Take all medicines regularly, as your doctor prescribes. Don’t change the amount of your medicine or skip a dose unless your doctor tells you to.
Doctors use several types of surgery to treat cardiomyopathy, including septal myectomy, surgically implanted devices, and heart transplant.
Septal myectomy is open-heart surgery and is used to treat people who have hypertrophic cardiomyopathy and severe symptoms. This surgery generally is used for younger patients and for people whose medicines aren’t working well.
A surgeon removes part of the thickened septum that’s bulging into the left ventricle. This improves blood flow through the heart and out to the body. The removed tissue doesn’t grow back. If needed, the surgeon also can repair or replace the mitral valve at the same time. Septal myectomy often is successful and allows you to return to a normal life with no symptoms.
Surgeons can place several types of devices in the heart to improve function and symptoms, including:
For this surgery, a surgeon replaces a person’s diseased heart with a healthy heart from a deceased donor. A heart transplant is a last resort treatment for people who have end-stage heart failure. “End-stage” means the condition has become so severe that all treatments, other than heart transplant, have failed. For more information about this treatment, go to the Heart Transplant Health Topic.
Doctors may use a nonsurgical procedure called alcohol septal ablation to treat cardiomyopathy. During this procedure, the doctor injects ethanol (a type of alcohol) through a tube into the small artery that supplies blood to the thickened area of heart muscle. The alcohol kills cells, and the thickened tissue shrinks to a more normal size. This procedure allows blood to flow freely through the ventricle, which improves symptoms.
Some people who have cardiomyopathy—especially those who have hypertrophic cardiomyopathy (HCM)—may live a healthy life with few problems or symptoms. Others may have serious symptoms and complications.
If you have cardiomyopathy, you can take steps to take care of your heart. Lifestyle changes and ongoing care can help you manage the disease.
A healthy diet and physical activity are part of a heart healthy lifestyle. Your doctor can help you decide what kind of eating plan is right for you. Talk with your doctor about the amounts and types of fluids that are safe and healthy for you. Too much fluid can worsen certain heart conditions.
Your doctor also may suggest a diet that's low in sodium (salt) and fat. (For more information about healthy eating, go to "How Is Cardiomyopathy Treated?")
Talk with your doctor about the amount and type of physical activity that's right for you. People who have HCM shouldn't do vigorous activity. However, moderate activity, such as walking, often is a good idea.
Your doctor also may suggest other lifestyle changes, such as:
If you have cardiomyopathy, it's important to get ongoing care. Call your doctor if you notice new or worsening symptoms, such as swelling in your ankles, feet, legs, abdomen, or veins in the neck. These symptoms may be a sign that the disease is getting worse.
You also should:
Cardiomyopathy often runs in families. Your doctor may suggest that your parents, brothers and sisters, and children get checked to see whether they have the disease.
The National Heart, Lung, and Blood Institute (NHLBI) leads or sponsors many studies aimed at preventing, diagnosing, and treating heart, lung, blood, and sleep disorders.
To learn more about clinical trials at the NIH Clinical Center or to talk to someone about a study that might fit your needs, call the Office of Patient Recruitment 800-411-1222.